Wireless communication devices have become smaller and more powerful as well as more capable. Increasingly users rely on wireless communication devices for mobile phone use as well as email and Internet access. At the same time, devices have become smaller in size. Devices such as cellular telephones, personal digital assistants (PDAs), laptop computers, and other similar devices provide reliable service with expanded coverage areas. Such devices may be referred to as mobile stations, stations, access terminals, user terminals, subscriber units, user equipments, and similar terms.
A wireless communication system may support communication for multiple wireless communication devices at the same time. In use, a wireless communication device may communicate with one or more base stations by transmissions on the uplink and downlink. Base stations may be referred to as access points, Node Bs, or other similar terms. The uplink or reverse link refers to the communication link from the wireless communication device to the base station, while the downlink or forward link refers to the communication from the base station to the wireless communication devices.
Wireless communication systems may be multiple access systems capable of supporting communication with multiple users by sharing the available system resources, such as bandwidth and transmit power. Examples of such multiple access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, wideband code division multiple access (WCDMA) systems, global system for mobile (GSM) communication systems, enhanced data rates for GSM evolution (EDGE) systems, and orthogonal frequency division multiple access (OFDMA) systems.
All wireless devices contain electronic chips which contain modems for transmitting and receiving, and may also contain additional processing functions and memories to support the multiple modes and functions of a smart phone. All of these features must be tested before the phone is delivered to a customer. As chips or system-on-chip (SoC) devices have gained functionality, the devices have become much more complex, with multiple cores and smaller and smaller devices and pins within one SoC. Testing such SoCs has become more difficult, as probing accurately requires a very small probe. In particular, it is difficult to get accurate measurements for critical specifications such as gain, isolation, harmonics, linearity, noise, and insertion loss due to high parasitic inductance.
There is a need in the art for a spring probe that adopts a guided transmission line concept which provides improved signal transition and minimum parasitic inductance at a low cost.